Jade awoke at the sound of her name with a groan that echoed Amber's earlier awakening. Hot... tense... Without thought her hands want to her breasts, tentatively playing across them through the thin fabric of her hand-me-down nightie; not quite daring to touch her nipples, biting her lip as the fabric dragged softly across them. But then she shifted her fingers to her stomach as she felt her organs move. Tracing the path with a forefinger as... something... shifted down. A premonition whispered in her brain... her ovaries. Changing, growing; converting their contents from eggs to something much more virile. Passing down through and closing first her womb, then her birth canal behind them. Shivering her flesh as sweat broke out across her body.
"Amber..." she breathed into the dark, shivering as the images of her changing gonads swam through her mind. Calling out to her trusted sister even though she had not consciously registered that Amber was awake. "What's going on... ahhhhh!"
Her question trailed into a soft, sensual moan as juices flooded out of her pussy, pushed ahead of her descending testes. A surge of heat pulsed from her clit, and her fingers shifted to it; scrambling to pull up her nightgown, finding it -- and her body jumping as she felt the sensitive bundle of nerves engorge and swell in her hand. Her urethra shifted up and merged into her glans; new ducts connected with the apparatus forming around her balls; her channel filling with masculine pre and the surrounding flesh with blood as her clit -- no, her cock -- surged aggressively against her touch.
"Ah! Oh God... whaaaa...!!"
Her other hand slipped down below it, just in time to feel her labia fusing into a soft sac of loose flesh. Again her question warped into a cry of animal pleasure, loud and unrestrained this time, as her balls dropped into her hand. Large, sensitive, jostling in their new home as they plumped with seed and drew the smooth skin tight; new hormones pumping into her body. She felt them rubbing against her thighs as her hips and legs twitched, her mind unable to keep up with the virile new pleasures. Wild desires implanted themselves in her brain, dark roots spreading through the fertile soil of unexplored fantasies.
Across the room, Amber threw aside her covers and slid out of bed. Jade heard her feet hit the carpet and looked over, just making out her fair skin. But Jade gasped as she saw glowing eyes piercing the dimness; the bright amber of her sister's namesake instead of her former brown, lit by primal, lustful fire. And red stained Jade's cheeks as her eyes trailed down her sister's heaving, naked bust to the proud, erect canid phallus, its red form darkly bold against her paler stomach; and the heavy shadow of her dangling balls.
"Amber..." Her voice shook with lust and wonder as she watched the pre ooze from Amber's tip, glistening in the moonlight as it ran down that elegant eight-inch obelisk.
"That's right, sis. Isn't it wonderful?" Amber placed a hand on her own new member, gasping huskily as she felt her powerful rod beating in her grasp. "Mmmm and I smell it... you're growing a cock too."
Her sister's acceptance was strangely comforting. Jade didn't understand... but if her sister was with her on this journey... she knew it would be okay. And it felt so good...! Her fearful confusion melted into pants of arousal as she fondled her balls and squeezed at her cock, feeling it push back, out of her fist, pointed and tapering. Making her shudder, her overheated body drenching her gown with sweat, the space under the covers turning into a fetid furnace. She didn't have to understand... just give in... let it out...
Despite her virginal ignorance, Jade knew what a penis should look like. And what her fingers felt was the wrong shape for a human. And yet... fear of the strangeness slipped farther from her. Deep in her brain and the marrow of her bones, it felt right.
While the bedclothes started to feel wrong... restrictive, oppressive. She flung them aside, turned and sitting up to face her sister. Her nightgown was rolled up, held behind her burgeoning red spire, displaying her round balls between her spread thighs. She had been naked in front of Amber before -- the only person she felt comfortable exposing herself around -- but never like this! Blushing as she felt her sister's lustful eyes on her new sex, feeling so brazen, so...
Liberated. Images began bubbling up from suppressed depths as primal urges pulsed through her from her cock into her brain, making her shiver with want. But she was not completely free, not yet. This nightgown, clinging around her, chafing her nipples, constraining her! Like her sheets, it needed to go! So she struggled out of it and cast it aside as well, feeling the heat and the musk radiate off of her skin.
"Aaaa... better..."
Her hands slid back to her loins, her eyes gazing down in awe past her big sweaty breasts. Breath quickening as she hefted her balls, now too big for her hand to contain; to dance her fingers gingerly over her... her cock! She couldn't believe what she was seeing, what she was feeling, what she was doing! She had rarely masturbated before, and never when her sister was in the room. But now she couldn't help herself... no she didn't want to stop! The seeds of wild passion sprouting in her mind and bursting the chains of her shame. Melting away her modesty, replacing it with an alien pride, still bashful yet growing with her cock.
"Ohh-ohhhhh..."
Her eyes closed as her loins changed still more in her hands, growing even more bestial. Feeling her ballsoft ballsack grow soft and velvety, her neatly trimmed pubes flowing out into lush, aromatic fur. Twin bumps pushing out from the base of her cock as she rubbed pre over the growing length, a budding knot; her shaft growing even harder and stronger as a baculum formed within.
"Oh Amber...!"
"Keep nnn going sis..." Amber whispered the encouragement as she watched, her eyes burning with intensity. Seeing Amber's own eyes kindle in the dark with green fire, smelling her growing musk joins hers in the heavy air. Slowly she pumped her own raging erection, her other hand now fondling her breasts, thumbing a nipple equally hard and erect. "You're... rrrgh!... turning out great..."
"Ahhh!" Jade flushed at the praise, feeling her pride and her cock surging. She -- she couldn't handle it any more! The weight of her balls, the might of her rod -- her hands couldn't contain them! And she let go, leaning back and bracing herself with her elbows on the bed as her hips began to buck. Gasping, she stared down at her bouncing cock, marvelling that it was hers but not able to deny the power pumping from it as it throbbed, the slick feeling as more and more pre leaked out from the pointed tip. Feeling her furry ballsack nudge heavily against her thighs, filling the once-empty space with potent fullness.
She gazed up at her sister through her eyelashes, seeing Amber's sexy, athletic body coming into clearer focus. Smelling her heady pheromones, a woman's scent mixed with canid maleness, flooded Jade's nostrils as they became more sensitive. And... herself... she knew her own scent, similar to her sister's but unique. Her own proud canid cock and balls would soon be complete, the powerful need for release growing ever stronger, threatening, inevitable.